On Monday, South Korean golfer Chun In-gee captured being reunited with her golf bag, which arrived late in Rio due to an airline mistake. She posted the photo on Instagram, saying: "Thank Goodness … I got my golf bag back just now! Let's move on!"

On the same day, Jamaican sprinter Usain Bolt celebrated on Twitter after he clinched the gold medal in the men's 100-meter with 9.81 seconds. He wrote: "Jamaica Stand Up!!! This for you my people." His fans retweeted the post more than 40,000 times. He also posted a video clip on Twitter to encourage fans to visit Rio and cheer for him.

U.S. swimmer Michael Phelps, who won five gold medals and a silver in Rio, also used social media to connect with fans. They left more than 4,200 comments after he won the 200-meter butterfly.

But athletes' social media use can sometimes be a double-edged sword.

South Korean volleyball player Park Jeong-ah's Instagram is now closed, because of netizens' insults. / Courtesy of Park Jeong-ah's Instagram

After the South Korean women's volleyball team failed to advance to the semifinals on Tuesday, the country's netizens wrote insults on Instagram, targeting Park Jeong-ah who failed to receive the Netherlands' ball 23 times. One netizen said: "Did you bet on South Korea's loss?"

Park's Instagram is now closed.

South Korean netizens also wrote insults in Korean on Honduran footballer Alberth Elis' Twitter after South Korea lost to Honduras in the quarterfinals on Aug 14.

They criticized Elis for allegedly faking injury. Some wrote racist comments.

Elis, who had closed his Twitter, soon reopened it and posted a picture showing him putting his index finger to his mouth.